1. Field of the Invention
The present invention relates to a recording apparatus of such a structure that recording means is mounted on a carriage which travels along a recording medium to record images on it by use of the recording means.
2. Related Background Art
A recording apparatus having the functions of a printer, copying machine, facsimile, and the like or a recording apparatus used as an output device for a complex type electronic equipment or a work station including a computer, word processor, and others, is structured so that images are recorded on a recording material (recording medium) such as a paper sheet and a thin plastic sheet in accordance with image information. These recording apparatuses can be classified as an ink jet type, a wire dot type, a thermal type, a laser beam type, and some others according to the recording methods to be adopted.
In a serial type recording apparatus which employs a serial scan method whereby to execute its main scanning in the direction orthogonal to the feeding direction (sub-scanning direction) of a recording material, the recording material is set at a given recording position; images are recorded (main scanned) by the use of recording means mounted on a carriage which travels along the recording material; subsequent to the completion of a one-line recording, the sheet is fed by a given amount (pitch feeding); then, the next line recording (main scanning) is executed on the recording material which has come to a stop again; thus, by repeating this sequence of operations, the entire recording on the recording material will be executed. On the other hand, in a recording apparatus of a line type where the recording is executed only by the sub-scanning in the feed direction of a recording material, the recording material is set at a given recording position; subsequent to the completion of a one-line recording collectively, the sheet is fed by a given amount (pitch feeding); then, by repeating the operations of executing the next line recording collectively, the entire recording on the recording material will be executed.
Among the above-mentioned recording apparatuses, the ink jet type recording apparatus (ink jet recording apparatus) is such that ink is discharged from recording means (recording head) onto a recording material for recording. With this type, it is possible to make the recording means compact and record highly precise images at a high speed. It is also possible to record on an ordinary sheet without any particular treatments given to it, thus providing inexpensive running cost. Having no impact, this type generates less noises. Also, among other advantages, this type of recording allows many different colors of ink to be used easily for recording color images.
Particularly, for an ink jet type recording means (recording head) which utilizes thermal energy for discharging ink, the one having the arrangement of highly densified liquid passages (discharge port arrangement) can be manufactured easily by forming the filmed electrothermal transducers, electrodes, liquid passage walls, a ceiling plate, and others on a substrate through the etching, vapor deposition, sputtering, and other semiconductor fabrication processes. It is thus possible to implement the provision of a more compact recording means.
Nevertheless, in a serial type recording apparatus such as this, there are the following problems encountered by its user when he attaches or detaches a member (an ink tank, a recording head, or the like, for example) to or from the carriage or operates a member mounted on the carriage (a member needed to adjust the space between a platen and a recording head, or the like, for example):
Firstly, if the carriage is not fixed to the carriage rails, it is not easy for the user to execute the above-mentioned operations because the carriage moves when the user attempts to do such operations.
Secondly, the forces exerted by such operations and others will affect the carriage to bend the carriage or the guide rails, making it difficult to execute the operations and others exactly or to cause the distance between the recording means mounted on the carriage and the platen to be varied inevitably. Then, the recording quality may be lowered. Particularly, in an ink jet recording apparatus, the variations of the space between the recording medium placed on its platen and ink jet recording head will produce adverse effects on the recording quality.
Further, in an ink jet recording apparatus, if its ink jet recording head cannot be located exactly in a position for capping or the carriage guide rails are bent, a problem is encountered in carrying out the capping for the head appropriately.
Now, in the serial type recording apparatus, the fixing method for the carriage in the main scanning direction has hitherto been such that the carriage is fixed manually when it is not in use or the carriage is brought to a stop position by an electrical system using a stepper motor among some others.
Also, there is a recording apparatus which is provided with a manual carriage locking mechanism as another fixing method. In this recording apparatus, the scanning is executed along the carriage guiding shafts arranged in parallel with the carriage platen, and when the recording apparatus is not in use, the carriage locking button which is provided for the recording apparatus is operated manually in order to fix the carriage so that it will not move in the scanning direction with respect to the carriage guiding shafts.
However, since the above-mentioned prior arts require the manual operation to fix the carriage, there are problems inherent in the user's manual operation that he forgets it or finds it troublesome. Also, the electrical positioning will present a problem that the forces will become insufficient to fix the carriage properly if the electric supply from its source should be somehow suspended. Therefore, it is difficult to fix the carriage reliably in either case. Also, it is difficult to avoid the bending of the carriage when the above-mentioned operations are to be executed in accordance with its requirements.